1. Field of the Invention
The present invention generally relates to laser generating apparatus and, more particularly, is directed to an end pumped solid-state laser.
2. Description of the Prior Art
A conventional end pumped solid-state laser is comprised of a resonator formed of a pair of mirrors and a laser rod (i.e., Nd:YAG laser rod), a laser diode for emitting a pumping light which excites the laser rod and a condenser lens for converging the pumping light from this pumping light source so that the converged light is irradiated on the end face of the laser rod.
When such laser generator is modified so as to generate a laser beam of large power, it is frequently observed that laser beams from a plurality of laser diodes are introduced into optical fibers forming an optical fiber bundle and the laser beam converged by this optical fiber bundle is irradiated through the condenser lens to the end face of the laser rod.
However, if the pumping light of large power is radiated on the end face of the laser rod, then temperature gradients of the radial and optical axis directions of the laser rod are increased to deteriorate the efficiency of the laser rod. Therefore, there is a limit on increasing the output power of the end pumped solid-state laser.